Hollow core–shell structured porous Si–C nanocomposites with void space up to tens of nanometres are designed to accommodate the volume expansion during lithiation for high-performance Li-ion battery anodes. An initial capacity of 760 mA h g−1 after formation cycles (based on the entire electrode weight) with 86% capacity retention over 100 cycles is achieved at a current density of 1 A g−1. Good rate performance is also demonstrated.